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Nanostructured pure and doped ceria catalysts for gas sensor applications

Saitzek S., Villain S., Fremy M.-A., Leroux C., Nolibe G., Gavarri J.-R.

Inżynieria Materiałowa

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2004

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R. XXV, nr 3

231-233

EN

For many years, CeO2 -based materials have been used as three-ways catalysts (TWC). They are also of great interest as solid electrolytes. It was already shown that nano-structured powders of cerium dioxide are more sensitive than micronic powders, for the detection of carbon monoxide CO or methane CH4 in air. By doping the cerium dioxide with various elements (Cu, V, Mn, ...), we try to improve the selectivity of the detection. The nanopowders of pure and doped cerium oxide were elaborated from "Sol-Gel" process. The structural characterization of these powders was carried out by X-ray diffraction and transmission electron microscopy. The atom fraction of doping element and the homogeneity of the powders were investigated by Energy Dispersive Spectrometry (EDS) microanalysis techniques. Finally, the catalytic activity was determined from (BET) adsorption techniques, spectrometry IR and electrical measurements involing a homemade device.

2

Nanoparticles of cerium dioxides for gas sensor applications.

Villain S., Leroux C., Musso J., Fremy M.A., Pischedda M.H., Gavarri J.R.

Inżynieria Materiałowa

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2001

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R. XXII, nr 5

935-938

EN

The aim of this work is to elaborate nanostructured cerium dioxides for catalytic and gas sensor applications. Nanosized cerium oxide powders were prepared via three chemical routes: 1) chemical precipitation followed by high-energy mechanical milling; 2) soft chemical preparation, 3) an unusual method of pulverization of liquid solution developed in our laboratory. The obtained powders were characterized using X-Ray diffraction analyses and Transmission Electron Microscopy experiments. Nanoparticles of pure CeO2 oxide having their sizes ranging from 2 to 10 nanometers have been obtained.

3

Design of selective layers for solid state electrochemical gas sensors

Josowicz M.

Chemia Analityczna

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2001

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Vol. 46, No. 2

161-174

EN

Conducting polymers offer a possibility for developing material properties that are critical to the sensitivity, selectivity and fabrication of potentiometric solid state gas sensors. The formation of charge transfer complex between the gaseous species and the semiconducting material results in chemical modulation of the work function of the polymer. Methods of primary doping of the conducting polymers that lead to a stable and adjustable value of the work function will be discussed using polyaniline as an example.

PL

Polimery przewodzące dają możliwość poprawienia tych właściwości materiałów, które decydują o czułości, selektywności oraz mają istotne znaczenie przy preparowaniu potencjometrycznych stałych sensorów na gaz. Tworzenie kompleksów z przeniesieniem ładunku między cząsteczkami gazu i półprzewodzącym materiałem prowadzi do zmian w funkcji pracy polimeru. W pracy przedyskutowano, na przykładzie polianiliny, metody domieszkowania przewodzących polimerów, które umożliwiają regulowanie i stabilizowanie wartości funkcji pracy.